How to change last character in string with a variable value.

Shell Programming and Scripting
1

Hey Guys,

I have text such as this.

28003,ALCORN,2
28009,BENTON,2
28013,CALHOUN,2
28017,CHICKASAW,2
47017,CARROLL,2
05021,CLAY,0

The last digit after the final "," is a variable value. This is the base file. I have to do further execution on this file later and I need to update the 3rd value at that time. So, How do I open this file, and append the last digit to my new variable, and also save as the same filename. I have tried multiple unsuccessful options.

An example of what I want is essentially the same output only with the new variable values appended. Using shell by the way.

2 
awk -F, '{$3=$3"new value"}1' file

Change red "new value" with whatever you want to append there.

3

Can it be a variable? Like $x

4 
awk -F, -vx=$x '{$3=$3""x}1' file
5

OK. Does the x in -vx represent the variable x? Is the $x the only time the variable is referenced?

Also. How would I do this in a loop. The script has to parse through the file appending if necessary, and not appending if not necessary. Obviously I'll need a "for" loop and an "if" statement. Just not sure how to set it up. Do I need to set your code to a variable itself?

Something such as
for.......
if argument is true
#append the third column in the file on this line only
else
#do nothing go to next line.
fi
done

6

-vx <- this "x" is awk's variable, while $x is shell's variable. You don't need shell's loop to go through all the lines. It can be done in awk. Just let me know what is the condition for appending.

7

There's so many way to scripting but I am not really sure if it is worth it.,,if ever that would be working if i use all the shell scripts in the same time..
My friend sharing me to all his information bout shell script but does not working don't know why i think it must be at the right shell programming before to function.. guys do you have any information regarding in this case if possible

Thanks for considerate:))

8

Ok. I'm just gonna lay it out there for ya. I'm not the best coder (obviously but here is what I have. Code is below.

#!/bin/sh
n=$(cat $fipslist | wc -l)
i=1
for ((i; i<n+1; i++))
do
  fipscode=$(cat $fipslist | head -$i | tail -1 | cut -c 17-21)
  countyname=$( cat $fipslist | grep $fipscode | cut -c 1-16 | tr -d " ")
  fipschecker=$(cat $cancountieslist | grep $fipscode" ")

  if [ "$fipschecker" != "" ]; then
    #echo $fipscode","$countyname","$threatcodecan >> $wcnoutput
    #HERE IS WHERE I NEED YOUR CODE.  RIGHT NOW IT JUST OVERWRITES $WCNOUTPUT.  BASED ON THE CONDITION ABOVE IN THE IF   STATEMENT, IF TRUE, I NEED IT TO JUST OPEN $WCNOUPUT, AND APPEND $THREATCODECAN (WHICH I HAVE ASSIGNED ELSEWHERE) TO $WCNOUTPUT IN THE THIRD COLUMN OF THE FILE (WHICH IS A CSV FILE).  LEAVING ALL OTHER LINES IN $WCNOUTPUT UNCHANGED.
  fi
done